Subcutaneous allergen immunotherapy for house dust mite reduced the number of prescriptions for allergic rhinitis and asthma medications, according to a study published in The European Journal of Allergy and Clinical Immunology. Compared with a control group that did not use allergen immunotherapy (AIT), the subcutaneous immunotherapy (SCIT) group showed a reduced probability for asthma onset as well as for developing asthma from allergic rhinitis (AR) over time, Marek Jutel, MD, PhD, professor and head of the department of clinical immunology at the Wroclaw Medical University and director of the ALL-MED Medical Research Institute in Wroclaw, Poland, and colleagues wrote. The retrospective, observational, comparative cohort study was conducted in Germany using anonymized claims data from IQVIA LRx.
Participants included house dust mite(HDM) allergic subjects aged 5 to 70 years divided into an SCIT group (n = 892) and a control group (n = 2,676) evaluated over a 6-year follow-up. Subjects in the SCIT group received their first prescription of SCIT with a native HDM product between 2009 and 2013. The control group was matched in a 3:1 ratio and received prescriptions for only symptomatic AR medication with an evaluation period of up to 6 years ending in February 2017. The study measured the progression of AR and asthma, asthma occurrence and time to the onset of asthma after at least 2 years of treatment.
Results:
The progression of AR and asthma after up to 6 years of follow-up was measured by counting numbers of prescriptions in the retrospective claims database analysis. Mean annual AR prescription numbers fell from 0.48 before the index to 0.17 in the follow-up period for the SCIT group for a 62.8% reduction (P < .0001) but remained the same at 0.48 for the control group. Subanalyses showed that children and adolescents initially had more allergic rhinitis prescriptions (mean, 0.54; standard deviation [SD], 1.06) than adults (mean, 0.45; SD, 1.1), which after follow-up showed a reduction in the SCIT group by 53% (P < .0001) in underage patients and 66.5% (P < .0001) in adults.
The mean number of asthma prescriptions in the SCIT group dropped by 2.51 a year compared with 1.63 in the control group. This was equivalent to a 42.4% reduction in asthma prescriptions in the SCIT group compared with the non-AIT group (P = .0003). The SCIT group showed comparable results in children/adolescents (47.2%; P = .0051) and adults (39%; P = .0166). Within the SCIT group, 10.2% developed asthma from the index date up to the 6-year follow-up, whereas 13.1% developed asthma in the control group. Logistic regression showed that the SCIT group had a 27% less chance of developing asthma than the control group (OR = 0.73; 95% CI: 0.559-0.954).
The authors concluded that the native HDM SCIT product was effective in preventing asthma.
Dr. Kenneth Backman of Allergy & Asthma Care comments: "This study reinforces previous data that has shown that allergen immunotherapy helps reduce the risk of asthma development, and improves control of allergic rhinitis and asthma symptoms."
